Methods for reducing odors in asphalt

ABSTRACT

Compositions and methods for reducing the foul odors of a hydrocarbonaceous material such as asphalt comprise the addition of an odor reducing amount of a reducing carbohydrate and/or a soluble zinc compound. The reducing carbohydrate may be a monosaccharide, oligosaccharide or polysaccharide, including a starch; and it may be used as a sole odor reducing agent or in combination with soluble zinc compounds and/or other odor reducing compounds.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.13/706,980, filed on Dec. 26, 2012, which claims priority to U.S.Provisional Application Ser. No. 61/567,673, filed Dec. 7, 2011, and isrelated to but does not claim priority from prior filed U.S. patentapplication Ser. No. 12/343,664, filed Dec. 24, 2008, the entirecontents of which are incorporated herein by reference.

BACKGROUND

The present invention relates generally to hydrocarbonaceouscompositions, such as asphalts and bitumens. More particularly thepresent invention generally relates to compositions for reducing thefoul, undesirable or unpleasant odors emitted from suchhydrocarbonaceous compositions.

Two primary uses of asphalt include road paving and roofing coatings.Asphalt-based roofing materials, such as roofing shingles, roll roofing,and built-up roofing, are installed on the roofs of buildings andresidential dwellings to provide protection from the elements. Whenasphalt is used in roofing applications, the asphalt is first heated ina vessel, such as a gas-fired roofing kettle. As the temperature of theasphalt rises, volatile materials, such as hydrocarbons, sulfides, andmercaptans, are emitted that can have strong, unpleasant, foul odors.The odors emitted are not only unpleasant to smell, but they may also bean irritant to workers and/or other individuals in the vicinity of thevessel or to those who come within close range of the hot asphalt. Forinstance, the odorous fumes from the asphalt may cause headaches and/orirritation to the eyes and mucus membranes of the nose and throat, whichcan result in a deterioration of worker productivity and/or in increasein the number of sick days taken by workers.

Although the properties of asphalts used in paving generally differ fromthose used in roofing coatings, the problem of heating and release ofvolatile and malodorous compounds is common to both roofing and pavingasphalts.

Many attempts to reduce undesirable odors emitted from odor-causingcompounds are known in the art. Non-limiting examples of some of theseapproaches and odor-masking additives are set forth below.

In a first approach, exemplified by U.S. Pat. No. 6,488,988 to Trumbore,et al. and U.S. Pat. Nos. 5,989,662 and 6,107,373 to Janicki, et al. aphysical barrier is formed on the surface of the asphalt to reducefuming. Trumbore teaches that a substantially insoluble blanket materialis added to the liquid asphalt to form a skin on the surface of theasphalt and reduce the fuming. Examples of blanket materials includepolyurethane, polyethylene terephthalate, ground soda bottles, starch,and cellulosic materials. Janicki, et al. disclose methods of reducingfumes produced from a kettle of molten asphalt that includes addingabout 0.25 to about 6.0% by weight of a polymer (e.g., polypropylene) tothe asphalt. The polymer material preferably forms a skin acrosssubstantially the entire upper surface of the asphalt. Janicki teachesthat at least a 25% reduction of the visual opacity of the fumes, atleast a 20% reduction of the hydrocarbon emissions of the fumes, and atleast a 15% reduction of suspended particulate emissions of the fumes isobtained.

In other approaches, essential oils are added as odor-masking compounds.For example, U.S. Pat. No. 5,271,767 to Light, Sr., et al. discloses acomposition that consists essentially of (1) liquid asphalt, hot-mixasphalt, hot-mix, or cold lay asphalt with added latex and (2) anadditive that contains a citrus terpene (4-isopropyl1-methylcyclohexene) D-limonene mixed with a vegetable oil such ascottonseed oil, soya oil, rapeseed (canola) oil, peanut oil, etc. and asilicone oil dispersant. It is taught that when 0.5-1.0 parts of thecomposition are mixed with 99.0-99.5 parts liquid asphalt, the resultingliquid asphalt composition is substantially free of objectionable odors.Also, U.S. Pat. No. 7,037,955 to Timcik and U.S. Patent Publication No.2006/0155003 to Timcik, et al. disclose methods for reducing odor in anoil based medium such as asphalt by adding an essential oil to theoil-based medium in an odor reducing amount. The essential oil may beone or more essential oils or essential oil components, and includesnatural extracts of various products of aromatic plants and trees.Essential oils for use in the invention include ajowan, angelica root,angelica seed, aniseed china star, carrot seed, and fir needle, amongmany others. Examples of essential oil components include terpenes,alcohols, aldehydes, aromatics, phenolics, esters, terpene derivatives,non-terpene essential oil components, and terpene derivatives.

In yet another approach, U.S. Pat. Nos. 6,461,421 and 6,987,207 toRonyak discloses compositions that include an odor-suppressing amount ofan aldehyde or a ketone along with a carboxylic acid ester; and, in thelatter case, also including a soy methyl ester. It is asserted that thecomposition significantly reduces the odor given off by ahydrocarbonaceous material such as asphalt.

Further, U.S. Patent Publication No. 2009/0314184 to Quinn, et al.discloses the use of certain aldehyde-containing compositions, with orwithout ketones but without esters, for reducing the malodors ofasphalts. The disclosed aldehydes include 2-chlorobenzaldehyde,4-chlorobenzaldehyde, alpha-methylcinnamaldehyde, 4-anisaldehyde,epsilon-cinnamaldehyde, vertraldehyde, 4-ethoxy-3-methoxybenzaldehyde,3-ethoxy-4-hydroxybenzaldehyde, 3-nitrobenzaldehyde, vanillin, andcinnamaldehyde. In exemplary embodiments the composition consists solelyof vanillin.

US patent Publication No. 2008/0146477 to Mentink, et al. disclosescertain compositions and methods for treating asphalts and bitumens, thecompositions containing certain specific esters of glutaric, succinicand adipic acids, or ethers or esters of a product derived from theinternal dehydration of a sugar. The purpose of Mentinck's compositionsappears to be a renewable source of additives to replace the current useof vegetable, mineral or fossil oils in the making of adjuvants forfluxes and binders for asphalts. The criteria set forth for theseadjuvants do not mention odor-reduction.

US Patent publication 2009-0145330 to Draper, et al, discloses the useof certain inorganic zinc compounds like zinc oxide, zinc sulfonate orzinc carbonate, typically in nanoparticle formats, for reducing theevolution of hydrogen sulfide from asphalts.

U.S. Pat. No. 4,147,212 to Tisdale discloses the use of water solublezinc ammonium carbonate salts for reduction of sulfides in drilling andworking with oil and gas. US Patent Publication 2009/0012214 to Butler,et al. describes the use of heavy metal, water insoluble soaps (e.g.zinc stearate) to alter the viscosity and/or rheological properties ofasphalts.

Thus there remains a need in the art for odor reduction using effectivethough low-cost compositions capable of reducing odors inhydrocarbonaceous materials such as asphalt.

SUMMARY

In one aspect, the invention relates to a hydrocarbonaceous materialhaving reduced foul odors. The hydrocarbonaceous material includes oneor more asphalts and an odor mitigating concentrate containing an odormitigating compound in an odor mitigating amount. The foul odors may bereduced relative to the asphalt in the absence of the odor mitigatingconcentrate. The odor mitigating compound may be selected from at leastone reducing carbohydrate, at least one soluble zinc compound, and acombination of both a reducing carbohydrate and a soluble zinc compound.

In another aspect, the present invention relates to methods for reducingfoul odors in hydrocarbonaceous materials like asphalts. In a firstvariation of the method, the undesirable odors of a hydrocarbonaceousmaterial may be reduced by adding to the hydrocarbonaceous material aconcentrate containing an odor mitigating amount of at least onereducing carbohydrate. In a second variation of the method, theundesirable odors of a hydrocarbonaceous material may be reduced byadding to the hydrocarbonaceous material a concentrate containing anodor mitigating amount of at least one soluble zinc compound. In a thirdvariation, at least one reducing carbohydrate and at least one solublezinc compound are both used to mitigate odors. Additionally, other knownodor reducing compounds may be present.

In some exemplary embodiments, the odor mitigating reducing carbohydratemay be mono- oligo- or poly-saccharide. The soluble zinc compounds mayinclude salts of C8-C20 fatty acids; for example salts of C12-C18 fattyacids.

One exemplary feature of the present invention is the reduction ofvolatile offensive gasses given off by asphalts, especially includinghydrogen sulfides and mercaptans (thiols).

Other advantages and features are evident from the following detaileddescription.

DETAILED DESCRIPTION

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which the invention belongs. Although any methods andmaterials similar or equivalent to those described herein can be used inthe practice or testing of the present invention, the preferred methodsand materials are described herein. All references cited herein,including books, journal articles, published U.S. or foreign patentapplications, issued U.S. or foreign patents, and any other references,are each incorporated by reference in their entireties, including alldata, tables, figures, and text presented in the cited references.

Unless otherwise indicated, all numbers expressing ranges of magnitudes,such as quantities of ingredients, properties such as molecular weight,reaction conditions, dimensions and so forth as used in thespecification and claims are to be understood as being modified in allinstances by the term “about.” Accordingly, unless otherwise indicated,the numerical properties set forth in the specification and claims areapproximations that may vary depending on the desired properties soughtto be obtained in embodiments of the present invention. Notwithstandingthat the numerical ranges and parameters setting forth the broad scopeof the invention are approximations, the numerical values set forth inthe specific examples are reported as precisely as possible. Anynumerical values, however, inherently contain certain errors necessarilyresulting from error found in their respective measurements. Allnumerical ranges are understood to include all possible incrementalsub-ranges within the outer boundaries of the range. Thus, a range of 30to 90 degrees discloses, for example, 35 to 50 degrees, 45 to 85degrees, and 40 to 80 degrees, etc.

Hydrocarbonaceous Materials and Bad Odors

The odor-emitting hydrocarbonaceous material may be anyhydrocarbonaceous material that emits at ambient temperatures orelevated temperatures undesirable or objectionable odors. Thesehydrocarbonaceous materials may be based on one or more natural oils,synthetic oils, or a combination thereof.

The mineral oils such as liquid petroleum oils and solvent treated oracid-treated mineral oils of the paraffinic, naphthenic or mixedparaffinic-naphthenic types often contain sulfur compounds. Oils derivedfrom coal or shale are also included. Synthetic oils may includehydrocarbon oils such as, for example, polymerized olefins,alkylbenzenes, polyphenyls, alkylated diphenyl ethers, alkylateddiphenyl sulfides, alkylene oxide polymers, esters of dicarboxylicacids, silicon-based oils, and the like.

Unrefined, refined and re-refined oils, either natural or synthetic (aswell as mixtures of two or more of any of these) of the type disclosedherein may be included. Unrefined oils are those obtained directly froma natural or synthetic source without further purification treatment.For example, a shale oil obtained directly from retorting operations, apetroleum oil obtained directly from primary distillation or ester oilobtained directly from an esterification process and used withoutfurther treatment would be an unrefined oil. Refined oils are similar tothe unrefined oils except they have been further treated in one or morepurification steps to improve one or more properties. Many suchpurification techniques are known to those skilled in the art such assolvent extraction, secondary distillation, acid or base extraction,filtration, percolation, etc. Re-refined oils may be obtained byprocesses similar to those used to obtain refined oils applied torefined oils which have been already used in service. Such re-refinedoils are also known as recycled, reclaimed or reprocessed oils and oftenare additionally processed by techniques directed to the removal ofspent additives and oil breakdown products.

The terms “asphalt” and “bitumen” are often used interchangeably, andrefer to any of a variety of hydrocarbonaceous pitch materials that aresolid or semi-solid brown or black masses at room temperature thatgradually liquefy when heated. They occur naturally in some regions ofthe world, and can be obtained as the residue of fractional distillationof petroleum. Asphalt is further described by Kirk-Othmer, Encyclopediaof Chemical Technology, Vol. 3, Third Ed. (1978) pp. 284-327, John Wiley& Sons, New York. An additional discussion appears in the publicationentitled “A Brief Introduction to Asphalt and some of its Uses”, ManualSeries No. 5 (MS-5), The Asphalt Institute, 7th Ed., September, 1974.Both of these references are incorporated herein by reference.

In accordance with some exemplary embodiments, the asphalts may includenatural asphalts and petroleum-refined asphalts which are generallyknown for roofing and paving applications. The natural asphalts mayinclude, for example, asphaltite such as gilsonite, grahamite and glancepitch; lake asphalt such as trinidad asphalt; and rock asphalt. Thepetroleum-refined asphalts may include (i) “straight” asphalt obtainedby distillation of a crude oil (unblown and substantially unoxidized),(ii) “blown” or “oxidized” asphalt produced by blowing anoxygen-containing gas into a straight asphalt in the presence or absenceof a catalyst, (iii) solvent-extracted asphalt obtained when asphalticmaterial is separated from the petroleum fraction containing it by theuse of propane or other solvents, and (iv) cut-back asphalt which is amixture of straight asphalt and a light petroleum solvent. In someexemplary embodiments, the asphalts include petroleum tar and asphaltcement. The petroleum tars include oil gas tar obtained as a by-productwhen gases are produced from petroleum fractions, such tar in refinedform, cut-back tar obtained by mixing a light petroleum fraction withsuch tar, and tar-pitch obtained as a residue by removing the volatilefraction from such tar. Any of these kinds of asphalt may be used singlyor jointly. Straight asphalt is useful for paving applications, andoxidized and blown asphalts are useful for roofing applications.

Such hydrocarbonaceous materials may contain one or more volatile (atambient or elevated temperatures) organic compounds (VOCs) such asaliphatic or aromatic hydrocarbons (e.g., methane, ethane, propane, oneor more butanes, pentanes, hexanes, benzene, and the like). In the caseof asphalts specifically, these and other VOC hydrocarbons, sulfides,and mercaptans may each contribute to the bad odor attributed toasphalt. The terms “foul”, “bad”, “malodorous”, “unpleasant”, and“undesirable” are all used interchangeably to characterize theobjectionable odor associated with asphalt. Such odors may be caused bymany of the above-mentioned compounds, but mercaptans (R—SH) andhydrogen sulfide (H₂S), even in small concentrations, contributesignificantly to the bad odor; the odor of “rotten eggs” is sometimesused to describe the foul smell.

The presence of these volatile compounds can be determined using knownanalytical techniques such as sensory electrodes and gas chromatography.The Honeywell Lumidor Micromax Plus is one sensory electrode instrument.It measures certain malodorous headspace gases such as H₂S, as well assome odorless gasses and others. One measurement, LEL, measures theLower Explosive Limit of combustible gases, such as methane, ethane,propane, butane, and others. Some of these are thought to contribute tothe foul odors of heated asphalt as well. Other specific undesirableVOCs are disclosed in Tables 1-24 of U.S. Patent Publication No.2009/0314184 to Quinn, et al., already incorporated herein in itsentirety, and include, for example, hydrogen sulfide, butane thiol,thiopene, 2-methyl thiopene, ethyl thiopene, pentane thiol, hexanethiol, dimethyl disulfide, dibenzothiophene, butyl dibenzothiophene,benzene thiol, methylbenzenethiol, o-cresol, p-cresol, phenol,dibenzofuran, quinoline, and decene.

In accordance with the present invention, an “odor mitigating amount” ofan odor mitigating composition is that quantity of the odor mitigatingcomposition that reduces at least some of the offensive volatileconstituents of the foul odors emitted from asphalt or otherhydrocarbonaceous materials. A useful measure of reduction is thefraction of VOCs remaining after treatment, compared to an equivalentuntreated control sample. Another measure is the related “percentreduction” from the baseline untreated sample. Either of these measuresmay be applied to specific individual VOCs or as an average reductionover multiple VOCs, as shown in U.S. Patent Publication No.2009/0314184. Thus, in some exemplary embodiments, an “odor mitigatingamount” shows an average reduction of at least 10%, at least 20%, atleast 25%, at least 30%, at least 40%, at least 50% or at least 60%. Insome exemplary embodiments, the average reduction may be from about 20to 95%, from about 30 to 90% or from about 40 to 80%.

In accordance with various exemplary embodiments, odor mitigatingcompounds added to the hydrocarbonaceous material in an odor mitigatingamount to reduce the unpleasant or objectionable odors. In someexemplary embodiments, the odor mitigating compounds may be added insmall increments up to 5% (weight/volume or “w/v”) of thehydrocarbonaceous material; e.g. from about 0.001% to about 5.0% w/v, orfrom 0.05% to about 1.0% w/v. In some exemplary embodiments, odormitigating compounds are added in small increments up to 1% w/v.

While the concentrations above are given for the ultimate dilution ofthe odor mitigating compounds in the hydrocarbonaceous material, it isoften preferable to prepare concentrated dispersions (or “concentrates”)of odor mitigating compounds in a carrier vehicle, and to add the liquidconcentrates to the hydrocarbonaceous material. Inventive odormitigating concentrates employing a carrier vehicle may comprise about1-50% by volume of odor mitigating compounds and about 50-99% by volumeof carrier. Dilution with a carrier vehicle may be particularly usefulwhere only a very small amount of compound is required to reduce odor,thereby facilitating handling of the additive. It is also easier tomeasure and add concentrated liquids to asphalt, than solids or powders.Dilution with a carrier may also help dissolve the compound in thehydrocarbonaceous material. In such cases, an inventive concentratecontains one or more odor mitigating compounds dispersed in a relativelyconcentrated dispersion in a carrier vehicle.

In some exemplary embodiments, the carrier vehicle is a liquid that isrelatively unreactive with the odor mitigating compounds. It should notcontribute malodorous compounds itself, but may even contribute to odormitigation. The odor mitigating compounds may soluble or dispersible inthe vehicle, and the vehicle may be miscible with the hydrocarbonaceousmaterial. In some exemplary embodiments, the carrier vehicles includecertain oils and certain polyethers. The carrier oils may include, forexample, mineral oil, vegetable oil, fatty acid alkyl esters, ormixtures thereof. Exemplary carriers include fatty acid alkyl esters ormixtures of fatty acid alkyl esters. The fatty component of the fattyacid ester may be linear or branched C8-C20 alkyl. Exemplary carriersmay include fatty acid methyl ester(s) and fatty acid ethyl esters; andalso methyl and ethyl esters of palm, coconut, canola, peanut,sunflower, and safflower oils. Suitable polyethers may includepolyethylene glycols (PEG). In some exemplary embodiments, the PEGcontains substituents that are nonionic and contain phenyl groups and/orhydrocarbon chains. Specific examples include octylphenol ethoxylatesand nonylphenol ethoxylates sold under tradenames TRITON X™ andTERGITOL™ (available from Dow Chemical, Midland, Mich.). Tergitol NP-4is one suitable carrier.

Reducing Carbohydrates

The invention generally relates to the use of reducing carbohydrates asodor mitigating compounds to reduce or mitigate bad odors emitted fromhydrocarbonaceous materials. In accordance with the present invention,“reducing carbohydrate” or “reducing sugar” means any carbohydrate/sugarthat either has an aldehyde functional group or is capable of formingone in solution through isomerisation. In some exemplary embodiments,this functional group allows the carbohydrate/sugar to act as a reducingagent to reduce certain chemicals. For example, in Benedict's reagentand Fehling's solution, both of which are used to test for the presenceof a reducing sugar, the reducing sugar reduces copper (II) ions tocopper (I), which then forms a brick red copper (I) oxide precipitate.

Many sugars with ketone groups in their open chain form are capable ofisomerizing via a series of tautomeric shifts to produce an aldehydegroup. Such isomermization may result from dissolution and/or thermaldecomposition. Therefore, ketone-bearing sugars like fructose may beconsidered reducing sugars. However, in some exemplary embodiments, itis the isomer containing an aldehyde group which is, since ketonescannot be oxidized without decomposition of the sugar. This type ofisomerization may catalyzed by the base present in solutions which testfor the presence of aldehydes. Monosaccharides which contain an aldehydegroup are known as aldoses, and those with a ketone group are known asketoses.

Simple monosaccharides exist in solution in ring form as a hemiacetal orhemiketal which gives rise to an additional chiral carbon, and to alphaand beta forms of each sugar. This additional asymmetric carbon is thecarbonyl carbon, and is also called the “anomeric” carbon since two“anomers” (i.e. alpha and beta forms) are formed depending on which sideof the flat carbonyl bond is attacked by the hydroxyl nucleophile.However, these closed rings may produce reducing sugars when thehemiacetal or hemiketal form isomerizes to the open or straight chainform, which contains the aldehyde or ketone functional group,respectively. Heat is a condition known to promote this isomerization.

However, the present invention is not limited to monosacharides.Disaccharides, oligosaccharides, polysaccharides, maltodextrins,dextrins and even starches may all have reducing capability and arewithin the definition of reducing carbohydrate/sugar if they have, orcan isomerize to have, an aldehyde group. While simple glucose has beenfound to be adequate, there may be advantages to longer polymers ofreducing sugars, by virtue of the additional molecular weight. In someexemplary embodiments, glucose polymers such as starch andstarch-derivatives like glucose syrup, maltodextrin and dextrin, themacromolecule begins with a reducing sugar, a free aldehyde. Morehydrolysed starch contains more reducing sugars. The percentage ofreducing sugars present in these starch derivatives (relative todextrose) is called the “dextrose equivalent” (DE). In some exemplaryembodiments, polymeric carbohydrates may (with or without hydrolysis)have a DE in the range of about 2 to about 70 for polymeric saccharides,and between about 70-100 for monomeric and oligomeric sacccharides.

Other reducing monosaccharides may include glucose, fructose,glyceraldehyde and galactose. Many disaccharides, such as lactose andmaltose, also have a reducing form, as one of the two units may have anopen-chain form with an aldehyde group. Sugars having (full) acetal orketal linkages are not reducing sugars, as they do not have freealdehyde chains. They therefore may not react with any of thereducing-sugar test solutions. Thus, sucrose and trehalose, in which theanomeric carbons of the two units are linked together forming an acetal,are non-reducing disaccharides since neither of the rings is capable ofopening.

The present inventive concepts may include any isomeric andstereochemical forms of these saccharides. Furthermore, derivatives ofsaccharides may also be suitable, provided they retain their reducingnature after derivatization or can regain reducing capability under therigorous heat conditions of asphalt processing. Thus, the saccharide mayinclude O-glycosides, N-glycosides, O-alkyl (e.g. methyl, ethyl),O-acylated sugars, amino sugars, sugar alcohols (like sorbitol, xylitol,erythritol, etc.) and the like.

In some exemplary embodiments, the reducing carbohydrates have amolecular weight greater than about 100 Daltons. In this context, theterm “molecular weight” is meant to denote a weight average molecularweight (in Daltons). In some exemplary embodiments, the reducingcarbohydrates have a molecular weight from about 100 to about 1,000,000,from about 120 to about 100,000, and from about 120 to about 10,000.

A single type of reducing carbohydrate may be used alone in an odormitigating amount; or it may be used in combination with other types ofreducing carbohydrates in an odor mitigating composition or concentrate,the odor mitigating composition in total being used in an odormitigating amount. Additionally, a single type of reducing carbohydrateor a combination of reducing carbohydrates in an odor mitigating amountmay be used in combination with other odor-mitigating compounds such as,for example, the vanillin-type carbonyl compounds and/or terpene-typeessential oil compounds known in the literature, or the soluble zinccompounds described herein.

While not intending to be limited to any particular theory of operation,it is believed that the reducing carbohydrates react with H₂S and/ormercaptan (thiol) compounds having the general formula R³—SH, andcomplex or sequester them, reducing their volatility. In some exemplaryembodiments, the reaction may involve the formation of hemithioacetalsor thioacetals (when the carbohydrate has an aldehyde) or hemithioketalsor thioketals (when the carbohydrate has a ketone. The followingreaction scheme illustrates a proposed reaction mechanism, but this isnot proven and not essential to the invention.

Structure I represents the reducing sugar, having an aldehyde functionalgroup when R=H and a ketone functional group when R¹=a carbon chain. R²represents the remainder portion of the sugar, which may cyclize with R¹to form the carbon chain of a ketone. Structure II represents malodorousmercaptans (thiols) where R³ is an aliphatic or aromatic chain, orhydrogen sulfide if R³=H. Structure III represents a hemi(thio)acetal orhemi(thio)ketal, depending if structure I is an aldehyde or a ketone,respectively. This reaction is analogous to the acetalation reactionwith alcohols, except that thiols are more reactive than alcohols inthis regard. In the presence of an excess of thiol compounds II, thereaction may proceed to structure IV, which is the full thioacetal orthioketal. Depending on the size and molecular weight of the sugarremainder R², and the mercaptan chains R³, a fairly large structure IIIor IV may be created, thus reducing the volatility of such compounds.

Soluble Zinc Odor Mitigating Compounds

In some exemplary embodiments, the odor mitigating compounds includesoluble zinc compounds. “Soluble” as used herein does not refer to watersolubility; but rather solubility in hydrocarbonaceous materials likeasphalts. ASTM procedure D2042-09 Standard Test Method for Solubility ofAsphalt Materials in Trichloroethylene is a useful test for solubilityof and in asphalts. As applied to roofing asphalts, the standardrequires a minimum of 99% solubility, such that less than 1% (by weight)of content of the asphalt is captured by the filter paper; 99% or moreis dissolved by the trichloroethylene. A comparable standard may be usedto define solubility in hydrocarbonaceaous materials; i.e. a compound is“soluble” as defined herein if at least 99% of added compound isdissolved in the trichloroethylene. Certain inorganic zinc compoundslike zinc oxide, zinc sulfonate or zinc carbonate are not “soluble” asthe term is used herein and are not within the odor mitigating solublezinc compounds of the invention.

Illustrative soluble zinc compounds include, for example, the salts of aC8-C20 fatty acid, for example salts of lauric acid (zinc laurate),myristic acid (zinc myristate), myristoleic (zinc myristolate), palmiticacid (zinc palmitate), palmitoleic acid (zinc palmitolate), stearic acid(zinc stearate), oleic acid (zinc oleate), linoleic acid (zinclinolate), and linolenic acid (zinc linolenate). Other zinc saltsinclude the salts of neodecanoic acid (zinc neodecanoate),2,4-dimethyl-2-isopropylpentanoic acid, 2,5-dimethyl-2-ethylhexanoicacid, 2,2-dimethyloctanoic acid, and 2,2-diethylhexanoic acid andnaphthenic acid, which is a mixture of cyclopentyl and cyclohexylsubstituted carboxylic acids, and 2-ethylhexanoic acid.

In some exemplary embodiments, the soluble zinc compound is a salt of aC12-C18 acid. In some exemplary embodiments, the even-numbered fattyacids are more prevalent naturally and less expensive, so it may beadvantageous to utilize salts of even numbered fatty acids in the C8-C20range or the C12-C18, such as laurate, myristate, myristolate,palmitate, palmitolate, stearate, oleate, linolate, and linolenate.

Other illustrative zinc compounds may include salts of modified fattyacids having from about 4 to about 20 carbons, the modificationsincluding (1) branching of the hydrocarbon chains, and (2) possessingsubstituents of hydroxyl, amino and carboxyl groups in the hydrocarbonchain, or (3) both (1) and (2). Notably, modified acids having aminosubstituents may include the natural or synthetic amino acids andmodified fatty acids having carboxyl substituents include dicarboxylicacids that may form ionic polymers with divalent zinc. When such zincsalts of modified fatty acids are also “soluble”, they are includedwithin the invention.

In some exemplary embodiments, the odor mitigating soluble zinccompounds are added to the hydrocarbonaceous material in an odormitigating amount to reduce the unpleasant or objectionable odors. Inexemplary embodiments, the soluble zinc odor mitigating compounds may beadded in small increments up to 5% (weight/volume or “w/v”) of thehydrocarbonaceous material; e.g. from about 0.001% to about 5.0% w/v, orfrom 0.05% to about 1.0% w/v. In some exemplary embodiments, odormitigating compounds are added in small increments up to 1% w/v.

Additional Odor Mitigating Compounds

In some exemplary embodiments, the odor mitigating compounds includealdehydes and ketones, such as, for example, those described in U.S.patent Publication 2009/0314184 to Quinn, et al., incorporated herein byreference. These compounds collectively are referred to herein as“carbonyl compounds” and have a molecular weight greater than about 100Daltons and a boiling point greater than about 375° F., or greater thanabout 400° F. and, in some embodiments, at least about 450° F. Specificexamples of such aldehyde-containing carbonyl compounds include2-chlorobenzaldehyde, 4-chlorobenzaldehyde, alpha-methylcinnamaldehyde,4-anisaldehyde, epsilon-cinnamaldehyde, vertraldehyde,4-ethoxy-3-methoxybenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde,3-nitrobenzaldehyde, vanillin, and cinnamaldehyde. In exemplaryembodiments the composition consists solely of vanillin. Specificexamples of such ketone-containing carbonyl compounds include, but arenot limited to, camphor, isophorone, isobutyrophenone, propiophenone,4-methylacetophenone, carvone, 4-chloroacetophenone, 2-benzoylbenzoicacid, 2′-acetonaphthone, benzophenone, fluorenone,4′-ethoxyacetophenone, 4′-chlorobenzophenone, 4-acetylbenzonitrile, and4′-hydroxyacetophenone.

These additional “carbonyl compounds” may be used in combination withreducing carbohydrate compounds and/or soluble zinc compounds describedherein.

Process of Use

Odor mitigating concentrates and compositions useful in the inventioncan be made by routine methods using the odor mitigating compounds.Carrier vehicles may be used if desired and are described above.

The compounds or concentrates may be added to the hydrocarbonaceousmaterial in various ways. In some exemplary embodiments, odor mitigatingcompounds or concentrates may be added to hydrocarbonaceous materials inhot-storage tanks. In other exemplary embodiments, the odor mitigatingcompounds or concentrates may be added to hydrocarbonaceous materialsthat are mixed with thermoplastic resins. In some exemplary embodiments,pellets of odor-reduced asphalt and resin are formed for dilution intoother thermoplastics in molding operations. In this way the asphaltpellets are diluted as filler to extend the resins and provide it withunique properties as is known in the art. In still other exemplaryembodiments, the odor mitigating compounds or concentrates may be added“on site” to kettles or drums of hot asphalt. For example, in built uproofing (BURA), asphalt is heated to about 350-450 F and many layers areformed as a composite roofing material. Paving asphalts are heated toabout 250-350 F. The high temperature at which these products aretypically used contributes to the volatility, as is known, although italso enhances the chemical reactions between the malodorous VOCs and theodor mitigating compounds, so as to enhance their elimination fromvolatile emissions.

EXAMPLES

The following examples serve to as illustrative embodiments and in noway limit the present invention.

Example 1 Preparation of Asphalt Samples

Three samples of asphalts were obtained from different sources andidentified as Tanks, #9, #17 and #43. The respective composition ofthese samples is set forth in Table 1 below.

TABLE 1 Sample Asphalt Compositions Tank #9 Tank #17 Tank #43Composition 100% MAP Detroit 100% Exxon-Mobil Oxidized Roofing Coating:of Asphalt Flux Joliet PG 64-22, 45% Country Mark Sample lightlyoxidized to 35.1% MooseJaw Type I with Softening 10% Exxon-Mobil JolietPG 64-22 Point of 145-150 F. 4.5% Conoco Phillips PG 52-28 4.5% ConocoPhillips Flux 0.125% Phosphoric Acid Initial Levels of: O₂ (wt %) 20.620.7 20.5 LEL* (%) 3 2 19 H₂S (ppm) 37 82 104 *LEL refers to LowerExplosive Limit, as explained herein.

Example 2 Testing of Carbohydrate Odor Reducers in Asphalt Samples

Carbohydrate compounds (samples F, G and H) were tested for odorreduction in each of the three asphalt samples from Example 1. Controlsincluded no additive (sample A), and two levels of vanillin additives astaught per US 2009/0314184 (samples B and C). The control andexperimental sample compositions are set forth in Table 2, below. Note,omitted compositions D and E tested odor control zinc compounds asdescribed in Example 3 below.

TABLE 2 Experimental odor reducing samples containing carbohydrates A BC F G H Asphalt composition from 300 300 300 300 300 300 Tank, 9, 17 or43 (g) vanillin 0 0.1 0.1 0 0 0 (g) polypropylene pellets (g) 0 0 3.6 00 0 Glucose (anhydrous) (g) 0 0 0 3 7.5 15

The 18 samples are thus designated by one of three tank numbers (#9, #17or #43) and one of six composition letters (A-C, F-H). In theexperiments, each of the 18 samples was mixed in a pint container untiluniform, and was then stored in an oven at about 380 F (193 C)overnight. The samples were transferred to a quart container with a ¼inch hole in the lid to allow for headspace gas analysis of hydrogensulfide (H₂S), carbon monoxide (CO) and lowest explosive limit (LEL)gases using a Honeywell Lumidor MicroMax Plus monitor. Since CO isodorless, its values were not felt relevant and not recorded here. Aninitial reading was observed for t=0, and the containers were stored inthe oven again at 380 F (193 C). The headspace gases were measured againat t=24 hours and t=10 days. The Lumidor was observed for peakmeasurements, and also at a consistent 2 minutes from opening eachcontainer. The Lumidor data, as well as some subjective observations areprovided in Tables 3, 4 and 5, below, in which tr=trace, sl=slight,N/A=not available.

It should be noted that headspace gases provide a reasonable measure ofthe odors emanating from asphalt when volatile components in the sampleliquid reach equilibrium with the headspace air. There are two instanceswhere this equilibrium is potentially not reached: (1) on the initialreading, where equilibration may not yet be reached; and (2) when a skinforms on the top of the liquid sample preventing the escape of volatilecomponents. The data in the Tables below is interpreted in light ofthese caveats. For example, the 24 hour measure is a better initialcomparison than t=0, and samples where a skin formed must be interpretedcautiously.

TABLE 3 Tank #9 Samples A B C F G H Initial H₂S (ppm) 2 4 3 2 2 4Initial LEL (%) 0 0 0 1 2 1 Initial Observations sharp H2S tr. H2S, tr.H2S, sl. burnt sl. burnt sl. burnt vanillin vanillin sugar sugar, gassugar, gas bubbles bubbles 24-hour H₂S-peak 128 95 70 45 42 23 (ppm)24-hour LEL-peak (%) 6 6 6 6 6 5 24-hour H₂S-2 min 61 27 33 25 22 12(ppm) 24-hour LEL-2 min (%) 4 4 4 4 4 4 24 hr Observations sharp H2S tr.H2S, tr. H2S, sl. burnt sl. burnt sl. burnt vanillin vanillin sugarsugar, gas sugar, gas bubbles bubbles 10 day H₂S-peak (ppm) 513 275 333235 182 220 10 day LEL-peak (%) 6 4 5 5 4 4 10 day H₂S-2 min (ppm) 191130 148 113 93 109 10 day LEL-2 min (%) 4 3 4 4 3 3 10 d Observations noskin, no no no solids tr. Solids tr. Solids H2S odor vanillin vanillinodor odor, pellets at edge

TABLE 4 Tank #17 Samples A B C F G H Initial H₂S (ppm) 43  44  41  22 10  4 Initial LEL (%) 2 2 2 2 1 1 Initial Observations strong strongstrong sl. burnt sl. burnt sl. burnt odor odor odor sugar; tr sugar, gassugar, gas vanillin vanillin solids bubbles, bubbles, solids solids24-hour H₂S-peak 29* 42  35  50  25  30  (ppm) 24-hour LEL-peak (%)  3*4 4 7 5 5 24-hour H₂S-2 min 11* 14  12  20  11  18  (ppm) 24-hour LEL-2min (%)  2* 2 2 4 4 4 24 hr Observations (all strong strong strong sl.burnt sl. burnt sl. burnt samples have some skin odor odor odor sugar;tr sugar, gas sugar, gas over surface) vanillin vanillin solids bubbles,bubbles, solids solids 10 day H₂S-peak (ppm) 3 24  5 18  17  17  10 dayLEL-peak (%) 1 1 0 1 1 1 10 day H₂S-2 min (ppm) 0 9 3 9 9 5 10 day LEL-2min (%) 0 0 0 0 0 0 10 d Observations (all no skin, non- non- tr.Solids, tr. Solids, skinned over) H2S odor vanillin, vanillin, burntburnt sour smell sour smell smell smell *a pump problem caused somedelay in testing sample A after opening the container

TABLE 5 Tank #43 Samples A B C F G H Initial H₂S 4 4 2 2 1 1 (ppm)Initial LEL (%) 0 0 0 0 0 0 Initial sl. odor sl. odor sl. odor sl. burntsl. burnt sl. burnt Observations vanillin vanillin sugar sugar, sugar,solids solids 24-hour 9 7 10  4 5 122*  H₂S-peak (ppm) 24-hour 1 1 2 1 1 8* LEL-peak (%) 24-hour 4 2 6 1 1  1* H₂S-2 min (ppm) 24-hour 1 0 1 0 0 6* LEL-2 min (%) 24 hr vanillin vanillin sugar sugar sugar Observations(all samples viscous with skin) 10 day 8 9 6 5 4 60* H₂S-peak (ppm) 10day 6 5 4 4 2 18* LEL-peak (%) 10 day 4 5 4 2 2 N/A* H₂S-2 min (ppm) 10day 3 2 2 2 1 N/A* LEL-2 min (%) 24 hr Observations (all samples viscouswith skin) *absence of ¼ inch hole in this container lid during storagelikely skewed these results; N/A due to high moisture flow clogging ofpump

It can be observed that the measures of offensive headspace gasses insamples containing carbohydrate compounds (F, G and H) were generallyequivalent or lower than control samples at initial times and, whilemost samples worsened over time, the effect of this was typically lesspronounced in samples F, G and H.

Example 3 Testing of Soluble Zinc Odor Reducers in Asphalt Samples

Soluble zinc compounds (samples D and E) were tested for odor reductionin each of the three asphalt samples from Example 1. Controls includedno additive (sample A), and two levels of vanillin additives as taughtper US 2009/0314184 (samples B and C). The control and experimentalsample compositions are set forth in Table 6, below.

TABLE 6 Experimental odor reducing samples containing zinc compounds A BC D E Asphalt composition from 300 300 300 300 300 Tank, 9, 17 or 43 (g)vanillin 0 0.1 0.1 0 0 (g) polypropylene pellets (g) 0 0 3.6 0 0 zincstearate (g) 1.5 6

The 15 samples are thus designated by one of three tank numbers (#9, #17or #43) and one of five composition letters (A-E). In the experiments,each of the 15 samples was mixed in a pint container and tested using aHoneywell Lumidor MicroMax Plus monitor, as in Example 2. The Lumidordata, as well as some subjective observations are provided in Tables 7,8 and 9, below, in which tr=trace, sl=slight, N/A=not available. Theequilibrium caveats mentioned in Example 2 apply here as well.

TABLE 7 Tank #9 Samples A B C D E Initial H₂S (ppm) 2 4 3 1 1 InitialLEL (%) 0 0 0 0 0 Initial Observations sharp H2S tr. H2S, tr. H2S, mildoil mild oil vanillin vanillin odor odor 24-hour H₂S-peak 128 95 70 3 1(ppm) 24-hour LEL-peak 6 6 6 11 8 (%) 24-hour H₂S-2 min 61 27 33 1 0(ppm) 24-hour LEL-2 min 4 4 4 7 6 (%) 24 hr Observations sharp H2S tr.H2S, tr. H2S, mild oil mild oil vanillin vanillin odor odor 10 dayH₂S-peak 513 275 333 179 10 (ppm) 10 day LEL-peak 6 4 5 6 6 (%) 10 dayH₂S-2 min 191 130 148 87 9 (ppm) 10 day LEL-2 min 4 3 4 522 522 (%) 10 dObservations no skin, no no no odor no odor H2S odor vanillin vanillinodor odor, pellets at edge

TABLE 8 Tank #17 Samples A B C D E Initial H₂S 43  44  41  2 2 (ppm)Initial LEL 2 2 2 0 2 (%) Initial strong strong strong mild odor mildodor Observations odor odor odor vanillin vanillin 24-hour 29* 42  35  72 H₂S-peak (ppm) 24-hour  3* 4 4 5 7 LEL-peak (%) 24-hour 11* 14  12  21 H₂S-2 min (ppm) 24-hour  2* 2 2 3 4 LEL-2 min (%) 24 hr strong strongstrong mild odor mild odor Observations (all samples odor odor odor havesome skin over surface) vanillin vanillin 10 day 3 24  5 8 4 H₂S-peak(ppm) 10 day 1 1 0 1 1 LEL-peak (%) 10 day 0 9 3 4 1 H₂S-2 min (ppm) 10day 0 0 0 0 0 LEL-2 min (%) 10 d no skin, non- non- Observations H2Sodor vanillin, vanillin, (all skinned sour smell sour smell over) *apump problem caused some delay in testing sample A after opening thecontainer

TABLE 9 Tank #43 Samples A B C D E Initial H₂S (ppm) 4 4 2 2 1 InitialLEL (%) 0 0 0 0 0 Initial Observations sl. odor sl. odor sl. odor trodor tr odor vanillin vanillin 24-hour H₂S-peak 9 7 10  5 4 (ppm)24-hour LEL-peak (%) 1 1 2 2 1 24-hour H₂S-2 min 4 2 6 4 0 (ppm) 24-hourLEL-2 min (%) 1 0 1 1 1 24 hr Observations (all vanillin vanillinsamples viscous with skin) 10 day H₂S-peak (ppm) 8 9 6 2 2 10 dayLEL-peak (%) 6 5 4 3 6 10 day H₂S-2 min (ppm) 4 5 4 1 1 10 day LEL-2 min(%) 3 2 2 2 4 24 hr Observations (all samples viscous with skin)

It can be observed that the measures of offensive headspace gasses(especially H₂S) in samples containing soluble zinc compounds (D and E)were initially lower than control samples and, while most samplesworsened over time, the effect of this was typically less pronounced insamples D and E.

The foregoing description of the various aspects and embodiments of thepresent invention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or all embodiments orto limit the invention to the specific aspects disclosed. Obviousmodifications or variations are possible in light of the above teachingsand such modifications and variations may well fall within the scope ofthe invention as determined by the appended claims when interpreted inaccordance with the breadth to which they are fairly, legally andequitably entitled.

What is claimed is:
 1. A method for reducing the undesirable odors of ahydrocarbonaceous material, comprising adding to the hydrocarbonaceousmaterial a composition containing an odor mitigating amount of at leastone reducing carbohydrate.
 2. The method of claim 1 wherein the reducingcarbohydrate is a monosaccharide.
 3. The method of claim 2 wherein themonosaccharide is glucose.
 4. The method of claim 1 wherein the reducingcarbohydrate is a polysaccharide.
 5. The method of claim 4 wherein thepolysaccharide has a DE from about 2 to about
 70. 6. The method of claim1 wherein the reducing carbohydrate is an oligosaccharide.
 7. The methodof claim 1 wherein the hydrocarbonaceous material is an asphalt.
 8. Themethod of claim 1 wherein the odor mitigating amount is from about0.001% w/v to about 5.0% w/v.
 9. The method of claim 1, furthercomprising adding to the hydrocarbonaceous material at least oneadditional odor mitigating compound.
 10. The method of claim 9 whereinthe at least one additional odor mitigating compound is selected from asoluble zinc compound or a carbonyl compound having a molecular weightgreater than about 100 Daltons and a boiling point greater than about375° F.
 11. A method for reducing the undesirable odors of ahydrocarbonaceous material, comprising adding to the hydrocarbonaceousmaterial a concentrate containing an odor mitigating amount of at leastone soluble zinc compound.
 12. The method of claim 11 wherein thesoluble zinc compound is a salt of a C8-C20 fatty acid.
 13. The methodof claim 12 wherein the soluble zinc compound is selected from salts oflauric acid, myristic acid, myristoleic, palmitic acid, palmitoleicacid, stearic acid, oleic acid, linioleic acid, and linolenic acid. 14.The method of claim 11 wherein the soluble zinc compound is a salt of aC12-C18 fatty acid.
 15. The method of claim 11 further comprising addingto the hydrocarbonaceous material at least one additional odormitigating compound.
 16. The method of claim 12 wherein the at least oneadditional odor reducing compound is selected from a reducingcarbohydrate or a carbonyl compound having a molecular weight greaterthan about 100 Daltons and a boiling point greater than about 375° F.17. The method of claim 11 wherein the hydrocarbonaceous material is anasphalt.
 18. The method of claim 11 wherein the odor mitigating amountis from about 0.001% w/v to about 5.0% w/v.